Execute method on startup in Spring

This is easily done with an ApplicationListener. I got this to work listening to Spring's ContextRefreshedEvent:

import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;

@Component
public class StartupHousekeeper implements ApplicationListener<ContextRefreshedEvent> {

  @Override
  public void onApplicationEvent(final ContextRefreshedEvent event) {
    // do whatever you need here 
  }
}

Application listeners run synchronously in Spring. If you want to make sure you're code is executed only once, just keep some state in your component.

UPDATE

Starting with Spring 4.2+ you can also use the @EventListener annotation to observe the ContextRefreshedEvent (thanks to @bphilipnyc for pointing this out):

import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;

@Component
public class StartupHousekeeper {

  @EventListener(ContextRefreshedEvent.class)
  public void contextRefreshedEvent() {
    // do whatever you need here 
  }
}

If by "application startup" you mean "application context startup", then yes, there are many ways to do this, the easiest (for singletons beans, anyway) being to annotate your method with @PostConstruct. Take a look at the link to see the other options, but in summary they are:

• Methods annotated with @PostConstruct
• afterPropertiesSet() as defined by the InitializingBean callback interface
• A custom configured init() method

Technically, these are hooks into the bean lifecycle, rather than the context lifecycle, but in 99% of cases, the two are equivalent.

If you need to hook specifically into the context startup/shutdown, then you can implement the Lifecycle interface instead, but that's probably unnecessary.

In Spring 4.2+ you can now simply do:

@Component
class StartupHousekeeper {

    @EventListener(ContextRefreshedEvent.class)
    public void contextRefreshedEvent() {
        //do whatever
    }
}